Wireless networks have experienced increased development in the past decade. One of the most rapidly developing areas is mobile ad hoc networks (MANETs). Physically, a MANET includes a number of potentially geographically distributed, potentially mobile nodes sharing one or more common radio channels. Compared with other types of networks, such as, cellular networks or satellite networks, MANETs have two distinctive features. First, MANETs lack any fixed infrastructure. Second, each node can act as a router to forward an upstream node's traffic to an ultimate destination, potentially many hops distant. The network is formed of mobile (and potentially stationary) nodes, and is created on the fly as the nodes communicate with each other. The network does not depend on any particular node and dynamically adjusts as some nodes join or others leave the network.
MANETs typically use dynamic routing capabilities. A routing algorithm ensures that data takes an appropriate, and hopefully the fastest, route to a destination node. Some MANETs could include multiple fixed base stations with “cut through” high bandwidth terrestrial links operating as gateways to fixed base stations or other services, including the Internet. It is possible to extend the MANET with only a minimal base station infrastructure. There are also many different types of routing protocols that can be used in a MANET, for example, an Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), Optimized Link State Routing protocol (OLSR) and Temporally-Ordered Routing Algorithm (TORA).
In more robust networks, nodes may be organized in one or more MANET clusters. For example, nodes in a certain geographic region or echelon may be assigned a cluster, or subnet designation. In some instances, a MANET cluster may include a subnet master node that organizes routing and communications within the cluster. More specifically, the master node may maintain a table having routing paths between other clusters, and current statuses of the nodes within the cluster.
Nevertheless, one drawback to this approach is a node in one cluster may be aware of other services available in the cluster via the master node, but may not be aware of other services in another cluster. In particular, in resource sharing applications, a resource need for a node could be filled by a node in another cluster, but the node may not be aware of such node's services, again because it is in another cluster. Moreover, another drawback to the clustering approach may be that the robustness of the MANET can be substantially altered when the master node is unavailable.
One approach is disclosed in the article titled, “Planning and Management of Dynamic Publish-Subscribe Communications In Tactical Networks Using Multicast Groups,” to Gadgil et al. This approach includes assigning multiple publication-subscription topics to each multicast group so that members of each group have similar information and service needs. The approach includes organizing the nodes into a two-tier hierarchy, i.e. including a central planner node and a plurality of dissemination nodes.
In one approach, a non-ad hoc static enterprise communication network is provided and comprises a plurality of permanent, i.e. nailed up, communication conduits. This approach provides current services that are subnet bound, or rely on statically designated proxy (i.e. “Application Level Gateways”). This approach may rely upon wired, stable, high bandwidth, hierarchical network connectivity, and may also rely on network routers and switches to support multicast traffic and static peering mechanisms. This approach may not be robust in a network comprised of MANETs since MANETs are inherently dynamic and typically have less bandwidth available.